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This CVE record has been updated after NVD enrichment efforts were completed. Enrichment data supplied by the NVD may require amendment due to these changes.
Description
In the Linux kernel, the following vulnerability has been resolved:
fbcon: Fix a NULL pointer dereference issue in fbcon_putcs
syzbot has found a NULL pointer dereference bug in fbcon.
Here is the simplified C reproducer:
struct param {
uint8_t type;
struct tiocl_selection ts;
};
int main()
{
struct fb_con2fbmap con2fb;
struct param param;
int fd = open("/dev/fb1", 0, 0);
con2fb.console = 0x19;
con2fb.framebuffer = 0;
ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);
param.type = 2;
param.ts.xs = 0; param.ts.ys = 0;
param.ts.xe = 0; param.ts.ye = 0;
param.ts.sel_mode = 0;
int fd1 = open("/dev/tty1", O_RDWR, 0);
ioctl(fd1, TIOCLINUX, ¶m);
con2fb.console = 1;
con2fb.framebuffer = 0;
ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);
return 0;
}
After calling ioctl(fd1, TIOCLINUX, ¶m), the subsequent ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb)
causes the kernel to follow a different execution path:
set_con2fb_map
-> con2fb_init_display
-> fbcon_set_disp
-> redraw_screen
-> hide_cursor
-> clear_selection
-> highlight
-> invert_screen
-> do_update_region
-> fbcon_putcs
-> ops->putcs
Since ops->putcs is a NULL pointer, this leads to a kernel panic.
To prevent this, we need to call set_blitting_type() within set_con2fb_map()
to properly initialize ops->putcs.
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OR
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 6.1.113
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.57
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.11.4
Changed
Reference Type
https://git.kernel.org/stable/c/5b97eebcce1b4f3f07a71f635d6aa3af96c236e7 No Types Assigned
New CVE Received from kernel.org10/21/2024 4:15:17 PM
Action
Type
Old Value
New Value
Added
Description
In the Linux kernel, the following vulnerability has been resolved:
fbcon: Fix a NULL pointer dereference issue in fbcon_putcs
syzbot has found a NULL pointer dereference bug in fbcon.
Here is the simplified C reproducer:
struct param {
uint8_t type;
struct tiocl_selection ts;
};
int main()
{
struct fb_con2fbmap con2fb;
struct param param;
int fd = open("/dev/fb1", 0, 0);
con2fb.console = 0x19;
con2fb.framebuffer = 0;
ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);
param.type = 2;
param.ts.xs = 0; param.ts.ys = 0;
param.ts.xe = 0; param.ts.ye = 0;
param.ts.sel_mode = 0;
int fd1 = open("/dev/tty1", O_RDWR, 0);
ioctl(fd1, TIOCLINUX, ¶m);
con2fb.console = 1;
con2fb.framebuffer = 0;
ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);
return 0;
}
After calling ioctl(fd1, TIOCLINUX, ¶m), the subsequent ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb)
causes the kernel to follow a different execution path:
set_con2fb_map
-> con2fb_init_display
-> fbcon_set_disp
-> redraw_screen
-> hide_cursor
-> clear_selection
-> highlight
-> invert_screen
-> do_update_region
-> fbcon_putcs
-> ops->putcs
Since ops->putcs is a NULL pointer, this leads to a kernel panic.
To prevent this, we need to call set_blitting_type() within set_con2fb_map()
to properly initialize ops->putcs.